gistfile1.txt

$ cat aa.scala && javap -c Foo.class Bar.class 
class Foo { val aa = 3 }

class Bar { def aa = 3 }
Compiled from "aa.scala"
public class Foo implements scala.ScalaObject {
  public int aa();
    Code:
       0: aload_0       
       1: getfield      #11                 // Field aa:I
       4: ireturn       

  public Foo();
    Code:
       0: aload_0       
       1: invokespecial #17                 // Method java/lang/Object."<init>":()V
       4: aload_0       
       5: iconst_3      
       6: putfield      #11                 // Field aa:I
       9: return        
}
Compiled from "aa.scala"
public class Bar implements scala.ScalaObject {
  public int aa();
    Code:
       0: iconst_3      
       1: ireturn       

  public Bar();
    Code:
       0: aload_0       
       1: invokespecial #12                 // Method java/lang/Object."<init>":()V
       4: return        
}